Nina Simone sings " You don't know what love is" ( until you've learned the meaning of the Blues) This heart-rending torch song ws written, strangely enough ,for a 1941 Abott and Costelo Fim. NOTE: They did not sing it to each other but was sung by a femle in the story.
Nina Simone captures the anguish expressed in both the words and music which song scholar Alec Wilder believed was written out of a personal conviction and wrote that" This is gloom in the raw, not the fake melodrama the commercial boys turn out."  

 https://youtu.be/BguiWbW5j3Q